The issue is complex and the war of words is fought over a few sentences in the T&C document.

Those who publish Android games on the Amazon App Store have no power to stop the retailer from making huge discounts – or offering the game for free – and paying developers as little as 20 per cent of a game’s listed value.

Also, every game published on the Amazon App Store has a ‘List Price’ – a set RRP that is equal to the lowest price of the game on other digital portals.

It means that, if a game is discounted on Apple’s App Store to £0.99, this will be the game’s List Price on Amazon.

IGDA pointed out that, under these circumstances, a game that is discounted for one week on a single app store would permanently lower Amazon’s List Price to the equivalent – even when the discount ends.

This had been a plan Amazon detailed in its Developer Terms And Conditions, yet the retailer has clarified that this deal wasn’t the case in another version of its T&C notice.

“We’d like to clear up some confusion about conflicting versions of our developer agreement,” the retailer said.

“There are both PDF and plain text versions on our developer portal, and these versions didn’t agree. The PDF version was correct; the plain text version was old. This has now been fixed.

“The old plain text version was outdated and didn’t show the updates we made to the agreement last November, including that the definition of List Price applies only to the app’s current price on a similar store.”

This would suggest that a list price can climb as well as fall, depending on prices on other app stores.

Amazon’s resistance to addressing any other concerns appears to have angered the IGDA.

“The majority of our concerns remain unaddressed,” the group said.

“Amazon is still reserving the right to pay developers just 20 per cent of their minimum list price at any time, without notification or advance approval.”

Driving its point, the IGDA said Amazon “is still unilaterally preventing developers from ever making an exclusive promotional deal with another marketplace”.

“Amazon's terms still enable it to steeply discount a game developer's content without permission -- a tactic Amazon could easily use to force game developers to absorb the cost for Amazon to compete with other app stores.”